Telegraph printer



July 2,1929. A. H. SHANGLE TELEGRAPH PRINTER Filed April 20, v 1928 //vv/v r01? Auas hf SHANGLE A ram/[y Patented July 2, 1929.

UNITED STATES PATENT OFFICE.

AMOS H. SHANGLE, OF ROSELLE, NEW JERSEY, ASSIGNOR TO BELL TELEPHONE LAB-. ORATORIES, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEGRAPH PRINTER.

Application filed April 20,

transmission which consists of periodically plugging a receiving printer into each of the circuits which converge at a central office. In applying thismethod of monitoring it has been found that considerable confusion and delay results from the difierences in the manner in which various so-called stunts are performed in the various circuits. For instance, some of the send ng printers are arranged to work in conjunction with receivingprinters which return the carriage from the shift to the normal position upon the receipt of a space signal and others unshift only when that code combination corresponding to the letters key is received. It is desirable thereforethat a printer which is to be used in monitoring service be readily adaptable to either class of service. i

In accordance, therefore, with the general features of this invent-ion the receiving printer is provided with a hand operated locking device which may be moved 1nto such a position that it engages a member projecting from the space stunt bar and thereby prevents a space signal from unshifting the printer carriage.

The operation of this device may be readily understood from the following description and the accompanying drawing which shows how this invention may be applied to one type of telegraph printer.

A complete description of the operation of the printer used to illustrate this invention is given in U. S. Patent 1,623,809. For the sake of clearness the elements not directly related to the operation of the locking device have been omitted in the present drawing, but enough of the printer structure has been included to show clearly how the device operates without the necessity of referring to the prior art. The various printer elements shown have been designated as in the drawings of the patent cited above 1928. -Serial No. 271,439.

in order that their relative positions in the printer may be easily found.

Referring now to the drawing, when a combination of impulses representing the space signal is received, the horizontal selecting bars 20 to 24 are so arranged that the special code or stunt bar 48 is permitted to move towardthe selecting bars under the action of its spring 57. The pull bar 168 connected at one end to the link member 129 and at the other to rocker arm 157 is moved downwardly to rotate the bell crank lever 158 and unshift the carriage, when the auxiliary striker bar 181 engages the heel member 58 at the rear of link member 129. This together with the other features of printer operation is fully described in the reference.

lVhen it is desired to use the printer to monitor a circuit in which the receiving printers should not unshift when a space signal is received, the monitoring operator turns the handle 1 into the position in which it is shown. The shaft 2 is rotatably mounted in a bracket member 9 which is secured to the frame of the printer and has a square section 8 which coacts with a spring member 4 to hold the device in whichever position it is set. The clamp 5 is securely attached to the stunt bar 48 and has a right angled extension piece 6 with an inclined surface 7 As the handle is moved in a counter clockwise direction into the position indicated, the stud 8 in the shaft 2 slides along this inclined surface, to its final position thereby holding the stunt bar away from the select ing bars and preventing the heel member 58 from moving backward intothe path of the auxiliary striker bar when the selecting bars are set in accordance with a space signal.

WVhat is claimed is:

1. In a receiving telegraph printer, printing mechanism, means responsive to received signals for selectively operating said mechanism, a stunt bar, means for moving said stunt bar to condition said mechanism, and manually operable means for locking said bar in a predetermined position.

2. In a receiving telegraph printer, printing mechanism, means responsive to received signals for selectively operating said mechanism, a stunt bar, means for moving said mined signal for unshifting said carriage, and means under the control of the attendant 10 of said printer for rendering said signal ineffective to unshift said carriage. In Witness whereof, I hereunto subscribe my name this 19th day of April, 1928.

AMOS H. SHANGLE. 

